Process and apparatus for crimping a multi-filament yarn



W. KISSLER Oct. 27, 1964 PROCESS AND APPARATUS FOR CRIMPING A MULTI-FILAMENT YARN Filed 061;. 1B, 1961 2 Sheets-Sheet 1 FIGI FIG. 2

FIG. 3

G1 W/ ([4] q 'IIIIIIIIIM INVENTOR. WOLFGANG KISSLER ATT'YS W. KISSLER Oct. 27, 1964 PROCESS AND APPARATUS FOR CRIMPING A MULTIi-FILAMENT YARN Filed Oct. 18, 1961 2 Sheets-Sheet 2 FIGS FIG. 6

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INVENTOR; WOLFGANG KISSLER ATT'YS United States Patent 3,153,891 PRGCESS Ahl) AlPARATUS FQR CRMPENQ A MULTl-FEAh IENT YARN Wolfgang Kissler, Dremmen, Bezirk Heinsherg, Germany, assignor to Vereinigte GlanZstofi-Fahriken AG, Wuppertal-Elberi'eld, Germany Filed Oct. 18, 1961, Ser. No. 145,856 Claims priority, application Germany Get. 19, 1960 14) Qlaims. (Cl. 5734) This invention relates to a process and apparatus for crimping a muti-filament yarn, i.e. a collection of individual filaments in the form of a yarn, thread, tow or the like. In particular, the invention is concerned with the crimping of yarn composed of a plurality of artificial filaments in order to improve the texture or handle of finished textil products manufactured from such yarn.

A number of processes are known in the prior art whereby it is possible to impart a crimp or twist in artificial filaments, the resulting filament deformation being fixed by the application of heat or similar fixing medium. One of the most common of these known processes is the socalled false-twist crimping method. In this method, the filaments are first softened or plasticized, and a false twist is then imparted to the filaments by a high speed twist spindle. It is thereby possible to provide a very high, uniform, temporary or false twist in a heated yarn, and upon cooling, a yarn can be obtained with a very high degree of crimping. However, this false-twist crimping method requires a relatively complicated and costly arrangement of apparatus, especially in connection with the false-twist spindle and the means to drive this spindle. The mechanical operation of the false-twist spindle presents very serious problems, particularly where it must be operated at speeds of 30,000 rev./min. or more.

An earlier method of fixing a temporary twist in a yarn was accomplished by first mechanically inserting a high twist, i.e. a true twist, into the yarn, then setting or fixing this twist by heat, and finally detwisting the yarn. Although a variety of processes of this type was developed, they were all very costly and quite slow because of the limited throughput of yarn. Therefore, this earlier method has been generally avoided in favor of the false-twist crimping method discussed above.

Still another group of crimping methods are known which are classified as producing a non-torque yarn by comparison with the torque yarns produced for example by the above-mentioned false-twist crimping method. One way of obtaining non-torque yarns or filaments is to force the yarn into a so-called stufiing box or crimping chamber such that the individual filaments are bent at random in difierent directions. The yarn is then fixed while compressed in the stuffing box, and the resulting yarn is removed from the box in its crimped condition.

A non-torque yarn is also obtained by drawing an untwisted yarn or individual filaments, either cold or heated, over a very sharp blade edge whereby a very high degree of physical deformation is imparted to each of the individual filaments. This technique is generally applicable only to a monofilament since it is quite difficult to control the crimping with a multi-filament yarn unless the filaments are carefully separated from each other while being crimped.

The chief objection to non-torque yarns is that it is almost impossible to obtain a regular and uniform crimping of the individual filaments. Thus, there is no way to control the random bending of individual filaments in the stufiing box. Another disadvantage of the stuffing box method is that the apparatus and its operation are quite expensive. With respect to the method of drawing a filament over a sharp blade edge, it was proven that an unheated and unfixed filament would initially exhibit a A 3,153,891 Patented Oct. 27, 1964 crimping effect, but this crimping would then disappear after a short period of time. Consequently, it became necessary to heat the filament to the fixing temperature prior to the time that it reached the sharp blade edge. The use of a sharp blade edge also causes problems in that it tends to sever or at least weaken the individual filaments so that filament breakage is quite common.

One object of the present invention is to provide a process and apparatus for crimping multi-filament yarns whereby serious disadvantages in prior art techniques can be avoided.

A specific object of the invention is to provide crimping apparatus which is inexpensive, easy to operate, and contains a minimum number of complicated moving parts.

Another specific object of the invention is to provide a process for crimping a multi-filament yarn which can be carried out in a continuous manner and with a. high throughput of yarn.

Still another object of the invention is to provide a crimping process which will produce a multi-filament yarn having a very high and uniform degree of crimping.

Yet another object of the invention is to provide a crimping apparatus as a novel combination including well-known and readily available component parts or parts which can be constructed at very low cost.

It has now been found in accordance with the present invention that a multifilament yarn can be textured or crimped in a very efiicient manner by means of a process and apparatus whereby the normal preliminary twist of a length of yarn between a supply point and a take-up point is accumulated into a shorter length, and the yarn heated for fixing of the twist in this shorter length.

The above objects and advantages of the invention and the manner in which they are accomplished will become more apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings in which:

FIG. 1 schematically illus rates one embodiment of an essential twist accumulating component in the combina tion of apparatus according to the invention;

FIG. 2 is a graphical representation of the distribution of twist over a length of yarn being treated by the appa ratus of FIG. 3;

FIG. 3 schematically illustrates on embodiment of apparatus elements combined in accordance with the invention;

FIG. 4 is a graphical representation of the twist distribution in a length of yarn which is being treated in apparatus according to FIG. 5;

FIG. 5 schematically illustrates a second embodiment of apparatus according to this invention wherein the twist of the yarn is accumulated and distributed between three separate stages;

FIG. 6 is a perspective view of one type of a twist accumulating device employed in accordance with the invention; and

FIG. 7 is a perspective view of a preferred twist accumulating device in accordance with the invention.

With more specific reference to the process of the invention, it is possible to texture or crimp a multifilament yarn in an efi'icient manner by drawing the yarn which contains a preliminary twist from a supply point to a take-up point, accumulating this preliminary twist which would normally be present in the length of yarn between the two points into a shorter length of yarn positioned intermediately the two points, and heating the yarn for fixation thereof in at least a portion of the shorter length in which the twist has been accumulated. In order to substantialy concentrate the preliminary twist in the yarn and in order to increase the number of turns in the yarn per unit length to a very high degree, it is an especially prefered procedure of the invention to accumulate the preliminary twist in a plurality of stages of adjacent lengths of the yarn, and it is also preferable to fix this yarn in the stage of maximum twist or maximum number of turns per unit length. By carefully regulating the conditions under which the twist in the yarn is accumulated and fixed, it is possible to provide a substantially uniform number of turns in the yarn per unit length in each of the twist accumulation stages.

The novel combination of apparatus according to this invention consists essentially of a number of members or devices which operate independently of one another over a length of multi-filament yarn, and these devices can be briefly described sequentially in the direction. of yarn travel as follows: supply means for furnishing a multifilament yarn containing a preliminary twist; a first twist barrier; a twist accumulator; a second twist barrier; and drawing or take-off means for pulling the yarn through a predetermined path. of travel from the initial supply means.

In this combination of apparatus, it is possible to use a number of elements which are quite conventional in this art. For example,.the supply means may be any suitable supply spool or bobbin, e.g. as received from the manufacturer, and the yarn may be wound on this supply spool with or preferably without a slight preliminary twist. A sufficient preliminary twist for the purposes of this invention can be obtained by drawing off the yarn in a direction corresponding to the spool axis, i.e. longitudinally of the spool, and the yarn is thus drawn off over one or the other end of the spool. It is an especially advantageous feature of the invention that when employing a supply spool wound with a completely untwisted yarn, a preliminary Z-twist or S-twist can be achieved in a very simple manner depending upon the placement of the spool on the supply or run-ofi spindle. Thus, if thesupply spool provides an S-twist when the yarn is drawn ofi over one end of the spool, it is possible to remove the spool, reverse it through an angle of '180 and replace it on the spool for removal or drawing off of the yarnover the opposite end of the spool, thereby obtaining a Z-twist. In this manner, the direction of the twist to be fixed in the yarn can be predetermined merely by placing the supply spool on its spindle such that the untwisted yarn is withdrawn over that end which provides an S-twist or over the opposite end which provides the Z-twist. A further obvious advantage of this arrangement is that the process of this invention does not require a supply spool in the form of a so-called uptwister in order to impart a preliminary twist to the The means for drawing the yarn from the supply spool and through the apparatus may also be of conventional construction. Such drawing ofi means generally include a take-up spool which isoperatively driven by its own spindle as a drive shaft or by a second roller. It is preferable to provide means for regulating the speed of the take-up spool so thatthe speed at which the yarn travels through the apparatus may also be carefully regulated.

The twist barriers employed in the apparatus of the inventionare any conventional means for preventing the twist in the yarn from running back from a predetermined point, especially to prevent the accumulated twist in the ya'rn from extending back to the supply spool. A satisfactory thread barrier is most conveniently obtained by employing a pair of nip rollers located along the path of the yarn in the usual manner.

The fixing device employed in this invention requires no special construction, since it is merely adapted to fix the accumulated twist in the yarn according to known principles. For the purposes of this invention, it is generally prefered to employ a fixing device in the form of an elongated, and closed or partially surrounded and heated chamber through which the twisted yarn is permitted to pass freely. The heat required for fixing may be supplied electrically through conductive metal plates, or else the heat be supplied by steam or a similar heat exchange fluid. Of course, the temperature at which the yarn is fixed should usually be carefully regulated according to the particular material or polymer in the filaments of the yam, The temperatures required for fixing various polymers are well known in the art.

The process and apparatus of this invention essentially require the use of a twist accumulator which includes 1 at least one and preferably two or more members pro vided with a smooth surface arranged in the yarn travel path. The object of the twist accumulator is to concentrate or collect the preliminary twist of. the yarn, for example, the slight twist imparted as theyarn is withdrawn over an end of the supply spool, such that there is an increase in the twist per unit length in the yarn preceding the point at which the twist accumulator is located. This accumulation at which the preliminary twist is essentially accomplished by pressing the smooth surface of the twist accumulator against the yarn and inwardly toward the longitudinal axis of the yarn, the pressure applied being sufficient to build up or increase the number of turns or twists in that portion of theyarn preceding the smooth surface, with reference to the direction of yarn travel. The applied pressure should never be so great as to rupture or break individual filaments in the yarn, and the contacting surface of the twist accumulator is preferably constructed of a non-corrosive metal so that the surface will remain smooth and non-abrasive.

The action of the twist accumulator can be more readily understood by comparison with the effect obtained if one ties a weight at the bottom of a twisted string and then pulls on the top of the string with one hand while compressing the string between thumb and forefinger of the other hand and sliding the fingers downwardly toward the weight. The result is to transfer torque to the weight causing it to turn at the bottom of the string. However, if the weight is clamped in a stationary position, the result is to increase the twist in the string be tween the fingers and the weight. The same increase or accumulation of preliminary twist is obtained in a similar manner between the twist accumulator and the first twist barrier. because the smooth surface or surfaces of the accumulator has the same relative longitudinal motion and frictional contact with the yarn being treated. In accordance withthis operation, the preferred twist accumulator of the invention is so constructed as to provide ttwo oppositely disposed smooth surfaces adapted to compress the yarn therebetween, for example by providing two plates having oppositely disposed and substantially parallel smooth surfaces and means to press these surfaces together against the yarn.

A very wide variety of multi-filament yarns can be successfully treated by the twist accumulating and fixing procedure of this invention. In general, a good torque crimping effect can be obtained with all artificial filaments, including regenerated natural polymers such as rayon and cellulose acetate and also including fully synthetic polymers such asnylon, polyethylene terephthalate, polyacrylonitrile, and the like. Furthermore, the multifilament yarns being treated need not be limited to any particular range of denier or number of individual filaments in the yarn. This flexibility in the process and apparatus of the invention constitutes a substantial adyantage over many prior art processes which, are useful only with relatively fine deniers and/ or a small number of filaments.

The individual steps of theprocess, the assembly of the apparatus and various preferred features of the invention can be more readily appreciated by referring to the drawings which exemplify and illustrate particular em bodiments of the invention and which are not intended to exclude other embodiments falling within the spirit and scope of this invention. V

, In FIG. 1, there is illustrated a single twist accumu:

lator consisting essentially of an upper plate 1 and lower plate 2 having smooth surfaces In and 20, respectively, these surfaces being substantially flat and parallel to each other and the two plates being pressed together so that the surfaces tend to compress the yarn Y as it is drawn in the direction of the arrow through the thread accumulator. A specific construction of this type of thread accumulator is illustrated in PEG. 7, whereas FIGS. 1, 3 and 5 illustrate this type of accumulator in schematic form (corresponding to the numeral 8 in FIG. 3 and the numerals 8, 9 and 10 in FIG. 5).

Again referring to FIG. 1, the length of yarn 4 emerging from a single accumulator has a twist or number of turns per unit length which corresponds approximately to the preliminary twist initially imparted to the yarn as it leaves the supply spool and before entering a twist accumulation stage. This condition results after a sufiicient length of yarn has been drawn through the accumulator to increase the number of turns per unit length to a maximum between the thread accumulator and the preceding twist barrier. A maximum number of turns is reached because the torque in the yarn preceding the twist accumulator eventually reaches a level which is equal to the maximum torque which can be transmitted to the thread by the twist accumulator. Thereafter, a state of equilibrium is attained whereby any turn or twist placed on the yarn in the system preceding the accumulator is compensated by a twist or turn being released from the discharge end of the accumulator. This state of equilibrium with a maximum number of turns in the length of yarn 3 will remain relatively stable for a continuous run of the same yarn, provided that all conditions affecting the yarn are otherwise kept as constant as possible. Of course, it will be recognized that the maximum number of turns of the twist accumulation will be dependent upon a number of factors, including the denier and number of filaments in the yarn itself, the pressure of the thread accumulator surfaces, the speed at which the yarn is drawn, and the like. The optimum conditions for any particular yarn can be readily determined by observing the final crimped product and making minor adjustments in the applied twist accumulation pressure to increase or decrease the amount of crimping desired.

In FIG. 3, there is schematically illustrated a complete combination of one embodiment of the apparatus according to the invention. This apparatus includes a supply spool 5, the yarn Y being drawn over one end of this spool and through a thread barrier 6 consisting of a pair of nip rollers. From this first thread barrier, the yarn is further drawn freely and without substantial friction through a suitable fixing device 7 such as a pair of electrically heated metal plates. The yarn then continues in its path through the twist accumulator 3 at which point the preliminary twist of the yarn is forced to back up toward the first thread barrier 6, and the number of turns per unit length of yarn increases between points 6 and 8 until the torque supplied by the yarn itself is in equilibri um with the restraining torque of the accumulator 8. At this equilibrium, the number of turns between 6 and 8 remains relatively uniform, and it is therefore ossible to fix this uniform twist by means of the heating element 7. Also, after this equilibrium state is reached, the yarn following the twist accumulator 8 has approximately the same number of turns per unit length as is contained in the yarn length preceding the first twist barrier 6. The yarn is finally drawn through the second twist barrier and onto the yarn take-up spool 12.

FIG. 2 provides a graphical indication of the relative amount of twist in the yarn at various points in the apparatus of FIG. 3. Points 13, 14 and 15 on the abscissa of this graph correspond respectively to the point at which yarn is drawn ofi of the spool 5, the twist barrier 6 and the twist accumulator 8. Points 15 and 17 on the ordinate of the graph indicate the number of turns in the yarn per unit length. Thus, the value 16 corresponds to the preliminary twist and 17 corresponds to the ac cumulated twist. As will be apparent from FIG. 2, after the equilibrium state has been reached in a con tinuous run of yarn, the number of turns per unit length at any point between the first twist barrier 6 and the twist accumulator 8 is constant. Also, after the accumulator 8, the number of turns per unit length again falls to the value 16 corresponding to the preliminary twist.

FIG. 5 corresponds to FIG. 3 except for the fact that there are three twist accumulators 8, 9 and 10 which are arranged sequentially at spaced intervals between the first and second twist barriers 6 and 11. This combination is especially advantageous because it provides a substantially greater accumulation of twise in the yarn to be fixed. As in the preceding embodiment, the yarn Y runs from the spool 5 through the first twist barrier 6, the fixing device 7, the twist accumulators 8, 9 and 10, the second twist barrier 11 and onto the take-up spool 12.

In FIG. 4, there is again plotted the number of turns per unit length at any point in the apparatus shown in FIG. 5. Thus, points 18, 19, 20 and 21 on the abscissa of this graph correspond respectively to the first twist barrier 6, and in succession, the twist accumulators 8, h and Ill. It will be seen that the value 22 represents the preliminary twist of the yarn as it leaves the spool 5 and that this amount of twist is again reached following the last twist accumulator it). As indicated by this graph, the preliminary twist 22 is first accumulated by the twist accumulator 1% to a value of 23, the twist is then further accumulated to a value of 24 by the twist accumulating member 9, and finally a total twist is accumulated from the value 24 to the final value of 25 by the first accumulator 8.

It has been recognized in accordance with the invention that the number of turns per unit length can be considerably increased if several twist accumulators are employed in succession rather than employing merely one twist accumulator. Thus, it is important to consider the difference between the torque appearing just before and just after the individual twist accumulator. In any system of this type, the torque in the yarn must always return to approximately the same Value as the preliminary twist after passing through one or more accumulating stages. Also, the maximum torque which an accumulator can apply is dependent upon the torque in the yarn emerging from this accumulator and does not depend upon the amount of preliminary twist. Therefore, by employing several accumulators, the last accumulator in the direction of yarn travel provides a first maximum torque, the next to last accumulator produces an additional maximum torque, and this procedure continues to the first accumulator where a final maximum torque is obtained.

Of course, the number of turns per unit length does not increase in linear dependency upon the number of accumulating stages, i.e. in no case can the number of turns achieved by two stages be equal to twice the number of those turns attained by one of the two stages. To the contrary, as the number of stages becomes greater, the additional increase in the number of turns becomes smaller and smaller and approaches a limiting value, after which a further increase in the number of turns per unit length can no longer be achieved by increasing the number of stages. This limiting value is naturally dependent upon the particular yarn employed, number of individual filaments, the type of twist accumulator used, etc.

Nevertheless, it is highly useful to employ a number of accumulating stages because it is still possible to obtain a very uniform twist at a maximum value of torque by employing relatively inexpensive and simple accumulating devices. Regardless of the number of accumulating stages, it is preferable to fix the yarn at a point between the first twist barrier and the first accumulator, in order to take advantage of the maximum amount of twist.

In principle, the second twist barrier 11 shown in FIGS. 3 and 5 would appear to be unnecessary. However, it

twist of 30 turns per meter.

has been found expedient to employthis second twist barrier because it has a very favorable effect in stabilizing the torque equilibrium of the one or more twist accumulation stages. Thus, the resulting crimping'is more uniform through the action of this second twist barrier in maintaining a constant number of turns per unit length of the yarn in each accumulation stage. Furthermore, where there are variable twist accumulations at the take-up spool, e.g. as caused by winding devices, such as thread guides, traverse-motion levers, deflection rods and the like, the second twist barrier 11 prevents the variation in torque from being propagated back into the length of yarn being fixed. Finally, the second twist barrier 11 provides a better defined thread clamping point after the accumu lation stage or stages, and the holding of the twist or torque at this point is important because in fixing the yarn the torque present on the yarn between the twist accumulator 8 in FIG. 3 or the last twist accumulator 10 in FIG. 5 and the take-up spool 12 must take place of the torque which is lost through softening of the yarn in the fixing operation.

As one example of a twist accumulator in accordance with the invention, it is possible to employ a simple deflecting rod 27. mounted on a supporting member 28 as shown in FIG. 6 of the drawing. In this case, the yarn is deflected as it passes over the smooth rounded edge of the rod- 27.' The pressure of this rod inwardly against the longitudinal axis of the running yarn tends to accumulate the yarn twist in that portion preceding the rod. The twist accumulation produced by such a rod is relatively small, so that this embodiment generally 'rquires a series of such rods with a corresponding number of accumulation stages.

A preferred type of thread accumulator is illustrated in FIG. 7, wherein the yarn Y is drawn between an upper plate 29 and lower plate 30 attached to support member 31. In order to prevent any abrasion of the yarn, it is preferable to round oif the leading edges 29a and 30a of the two plates. Four pins 32 are connected firmly to the lower'plate 30 and extend perpendicularly therefrom in alignment and sliding engagement with channels or openings in the upper plate 29. The oppositely disposed and parallel surfaces of the two plates 29 and 30 are spring urged toward each other by helical springs 33 held in compression by an adjusting nut 34 mounted on the threaded end of each of the pins 32. With this construction, the amount of pressure directed inwardly against the longitudinal axis of the yarn Y can be very carefully regulated.

In order to obtain a yarn product with a satisfactory texture and a high and uniform crimping effect, the process and apparatus of this invention are adapted to provide a high ratio of accumulated twist to preliminary twist, defined as T,,/T where T is the maximum number of turns per meter in the yarn preceding the first or only twist accumulating device and T is the number of turns per meter of preliminary twist obtained by drawing an untwisted yarn from one end of a conventional supply spool. Although the ratio T T can vary over a wide range depending upon yarn characteristics such as denier and number of filaments, the yarn draw speed, the number of twist accumulators and the like, it is an object of this invention to work at a T,/ T p value between 50 and Example 7 'A single twist accumulator as illustrated in FIG. 1 and FIG. 7 was used to crimp a 90 den. polyarnid thread (Perlon) with 18 filaments and a preliminary By drawing the yarn through the apparatus with a speed of 100 meters per minute a twist of 3000 turns per meter was reached by the twist accumulator. The yarn passed the heating box accumulator 8. (7) unsupported. The heating box had a length of 70 cm. and the temperature of the air in the box was about 189 C.

The resulting crimped yarn had a crimp contraction.

of 65%, a crimp elongation of 200% and a strength of 350 g./10O den.

The invention is hereby claimed as follows: 1. A process for crimping a multi-filament yarn which comprises drawing said yarn containing a. preliminary twist from a supply point to a take-up point, accumulating said preliminary twist normally present in the length of yarn between said points into a shorter length'positioned intermediately said points, and heating said yarn for fixation thereof in at least a portion of said shorter length in which the twist has been accumulated.

2. A process as claimed in claim 1 wherein said preliminary twist is accumulated in a plurality of stages of adjacent lengths of yarn, the number of turns in the.

yarn per unit length being a maximum in the first stage and decreasing in each succeeding stage, said first stage corresponding to the accumulation of yarn twist nearest the supply point and each succeeding stage following in the direction in which the yarn is drawn.

3. A process as claimed in claim 2 wherein the twist is accumulated to provide a substantially uniform number of turns in the yarn per unit length in each of said stages.

4. Apparatus for crimping a multi-filament yarn comprising in combination: means to supply said yarn with a preliminary twist; means for drawing said yarn from said supply means through a predetermined path of travel; a twist accumulator having at least one smooth surface which is arranged in said yarn travel path for application of pressure by said surface against said yarn and inwardly toward the longitudinal axis of said yarn and which is adapted to accumulate said preliminary twist in that portion of the yarn preceding said surface with reference to the direction of yarn travel; a first twist barrier arranged in said yarn travel path between said supply means and said twist accumulator; a second twist barrier arranged in said yarn travel path between said twist accumulator and said drawing means; and means located between said first twist barrier and said twist accumulator for fixing the twist accumulated in said yarn.

5. Apparatus as claimed in claim 4 wherein said twist accumulator has two oppositely disposed smooth surfaces adapted to compress said yarn therebetween.

6. Apparatus as claimed in claim 4 wherein a plurality of twist accumulators are arranged at spaced intervals in said yarn travel path between said first and said second twist barriers. 1 V

7. Apparatus as claimed in claim 4 wherein said twist accumulator consists of a member having a smooth rounded edge as the surface for applying pressure against said yarn.

8. Apparatus as claimed in claim 4 wherein said twist includes two plates having oppositely disposed substantially parallel smooth surfaces and means to press said surfaces together against said yarn.

9. A process as claimed'in claim 1 wherein the ratio of said accumulated twist to said preliminary twist, defined as T,,/ T is equal to at least about 50.

10. A process as claimed in claim 9 wherein the value of T,/T,, is about to 200.

References Cited in the file of this patent 9 UNITED STATES PATENTS 463,589 Wimmer Nov. 17, 1891 2,673,442 Long Mar. 30, 1954 2,788,634 Crouzet April 16, 1957 2,931,089 Evans Apr. 5, 1960 3,025,584 Evans Mar. 20, 1962 3,069,837 Olson Dec. 25, 1962 FOREIGN PATENTS 164,127 Australia July'15, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,153,891 October 27 1964 Wolfgang Kissler It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 44, for "on" read one column 6, line 14, for "twise" read twist Signed and sealed this 16th day of March 1965 (SEAL) Attest:

ERNEST W. SWIDER v EDWARD J. BRENNER Awttesting Officer Commissioner of Patents 

4. APPARATUS FOR CRIMPING A MULTI-FILAMENT YARN COMPRISING IN COMBINATION: MEANS TO SUPPLY SAID YARN WITH A PRELIMINARY TWIST; MEANS FOR DRAWING SAID YARN FROM SAID SUPPLY MEANS THROUGH A PREDETERMINED PATH OF TRAVEL; A TWIST ACCUMULATOR HAVING AT LEAST ONE SMOOTH SURFACE WHICH IS ARRANGED IN SAID YARN TRAVEL PATH FOR APPLICATION OF PRESSURE BY SAID SURFACE AGAINST SAID YARN AND INWARDLY TOWARD THE LONGITUDINAL AXIS OF SAID YARN AND WHICH IS ADAPTED TO ACCUMULATE SAID PRELIMINARY TWIST IN THAT PORTION OF THE YARN PRECEDING SAID SURFACE WITH REFERENCE TO THE DIRECTION OF YARN TRAVEL; A FIRST TWIST BARRIER ARRANGED IN SAID YARN TRAVEL PATH BETWEEN SAID SUPPLY MEANS AND SAID TWIST ACCUMULATOR; A SECOND TWIST BARRIER ARRANGED IN SAID YARN TRAVEL PATH BETWEEN SAID TWIST ACCUMULATOR AND SAID DRAWING MEANS; AND MEANS LOCATED BETWEEN SAID FIRST TWIST BARRIER AND SAID TWIST ACCUMULATOR FOR FIXING THE TWIST ACCUMULATED IN SAID YARN. 